Press



April 11 1933- A. A. BYERLEIN 1,903,438

PRESS Filed Feb. l, 1932 Patented Apr. 11, 1933 UNITED STATES PATEN T. OFFICE ARTHUR BYER/LEIN, OIE DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MACHINERYI CORPORATION, OF HAMILTON, OHIO, A CORPORATION F' DELAWARE 1 PRESS' f Application fmea February 1,'1932. serial no. 590,059.

' .This vinvention relates to.` presses, and more particularly to presses for drawing sheet metal and the like.- One object of the invention, is theprovision of a drawing press having a press bed in which are arranged upper and lower fluid pressure chambers forming a pressure cushion cooperating with-the pressure ring, the movable elements ofthe `upper and lower fluid pressure chambers being connected lexternally of the chambers forV simultaneous movement. l

Another object of the invention is the provision of a fluid pressure cushion of thecharacter described having `upper and lower cylinder elements and piston elements, the movable parts of the cushion being connected vfor simultaneous .movement in a"fnovel manner, designed to rovide for a minimum amount of leakage o pressure fluid from the cushion.

" Other objects andfadvantages ofthe invention will be apparent from the following description, the appended claims and the accompanying dra-wing, in which- Fig. 1 is a frontview, partly in section, showing the lower portion of a drawing press embodying the present invention;

Fig. 2 is a vertical section taken centrally through one of the. pressure cushions and through the pressbed;.and Y Fig. 3 is a section on the line `3--3 of Referring .more particularly to the drawing by reference numerals, 10 designates'the frame of apress for drawing or forming sheet metal'or the like, only the lower. portion of which is shown as the top portion may be of any conventionalcharacter of the single or double acting type.v This frame embodies uprights 11,l thelower parts' of 40 which form portions of the press bedwhich Y is generally designated by the numeral 12.

On the bed 12 is a bolster plate 14 which supports a lower die 15. :Surrounding the lower die 15 is a pressure ring or ejector ring 16, supporting the peripheral :edges -of the sheet metal blank 17.` The pressure ring 16 is supported by a series of pins 18V that project up throughholes in the bolster plate, the lower ends of these pins resting on pressure plates provided in thev bed of the press. "As

herein shown the pressure ring is supported l by twov fluid pressure cushions horizontally :spaced apart and providedrinthe two' wells 0r openings 2O of the press bed. Thesecushions contain air'or other fluid under pressure. 55 While -twolpressure cushions have been illustrated, it will be `understood that the `press may haveonly one pressure cushion, lor three or more pressurecushions maybe provided,` especially in presses of the larger sizes adapt- '560 ed for operation on very large sheets of metal. These pressure cushions, which have been generally designated by the numeral .21, serve to exert a desired pressure on the Vpins 18 causing the peripheral portions' of themetal '5615l i plate tobe held VyieldinglyunderL a predetermined pressure between the pressure ring 16 and the .lower side ofthe upper die, which hasnotbeenshownj In accordance with the present invention, -70 each ofthe pressure cushions121 has a plue -ralityof fluidv pressure chambers, eachA chamber being preferably formed by upper and n lower telescopically engaged piston and cyl- Vinder elements,'the movable elements of the 375 Cushion being connected together so as to operate in unison in order that thetotalpressure exerted by the cushion onthey pins. 18

will bev twice the value that would beV exerted by a cushion having a 'single air space `or80 chamber and operating under the same air4 pressure conditions. The doublel or multiple. arrangement of pressure chambers as herein rshown permits the fluid pressure, that is the pounds per Asquare inch pressurefexerted :ini-'85 the fluid pressure chambers to be .kept comparativelyv small although Vgreat pressures may be exerted `on the top' pressure plate-and on the pressure ring. Moreover; in accord-V ance with the novelarrangement asherein set forth, there is a minimum of leaka e of` the pressure Huid from theV pressure cus ions as the connection fromr the top movable element to the lower movable element "of the 4 cushion does not extend centrally through either the pressure chamber,fbut on the con. trary is arranged outside thecushionfso that thereis no packed bearing .or joint extending through a cushion wall.. l1 ,i Y The two pressure chambers of,` thewfluid bed by the guide surfaces 30 that are -pref erably removably secured in the corners of the press bed and nwhich vinterlit with notched-out corner portions of the pressure pad so'as to support the pressure pad. for vertical sliding movement but prevent' any vlateral movement thereof.

p'Ihe bottom wall 32 of the pistonelement 26 is extended out laterally, 4forming the ledges 33, the outer portionszof these ledges being-supported by downwardly extending wallsf34that may. befmade integral lwith vthe ledges 33l soV that the walls 34 constitute .an integral part of the' piston element. f These walls 34rest on a cross plate 36 thatis secured' by bolts: 37 to the lower side of the press bed, bolts 38 fixing the walls 34 in place in a rigid and secure manner. By reason of this construction the lower or piston element of the top fluid pressure chamber'23`is supported in fixed position so that as the cylinder element is 'pushed down, wheny the pressure ring is forced down, the air or other fluid -contained under pressure in the pres- Y Y.sure chamberV will serve to exert adesired pressure upwardly on the pressure lring returning it upwardly after the top dichas beenl raised away-from the completed work.

VThe lower side of the bottom .wall 32 has n aflat surface40 and this surface is normally engaged vbytheflat top surface' of a second '-pressurefpad 41l forming a part o-f a cylinder element 42 of the lower fluid pressure chamber 24. The cylindrical walls of this cylinder e element42'are.telescopically engaged by cy- Iindrical portions of the pistonelement 45 lwhich has a-bottom wall 46 `resting on the cross platev 36. Suitabley packing as yindicated at 47 may be provided to preventleakage past fthe telescopically engaged surfaces of thefluidpressure chamber.v The upperor movable element of chamber 24 isadapted to be moved by means of pins'49 provided at cushion axis so that they are provided externally of the walls of the fluidpressure chambers. i These-pins 49v extend freely throughV @l5 to thevpressure pad 29, to which fluid pressuitable'points spaced laterally from they sure exerted by the upper cushion is also applied. The pad thus trans-mits the force of both cylinders directly to the pins 18. Asy

Vmovable yconnections extending through a wall of the cushions and consequently there isa minimumamount o f'leakage of pressure fluidL from the 'cushionsf It will be understood that the air -or other pressure fluid contained in the cushions will be equalized, sinceboth cushions are supplied from a common pipe, and any increase or cliangefof Vpressure in one chamber will 'beequalized with the pressure o`f the other.

The-compressed air fromv the building air vsupplyis supplied through a check valve and through a suitable pressure regulating valve tothe pipe 53 which transmits it to the cushion at a controlledpressure depending` on the particular character of-the work to be performed. lThe check valve prevents back flow of air from the cushions to the supply line when the cushion elements are collapsed or partly collapsedV toward one another and the pressure is `raised above the normal pressure obtaining when thefchambers are of Imaximum volume.` The pipe 53 is connected Vto a passage 5 4provided preferably'in a bottom yportiony of the lower piston element, and a branch. pipe 554 extends up to aipassage56 vrprovided in the pistonv element 26.

- In accordance with the described arrangement, itnwill be apparent that/the double fiuid pressure'cushionv is ofl very simple conscribed constitutes a; preferred embodimentl of the invention, it is'to be'understood that the invention is not limited to this precise form of apparatus, and lthat changes may be madetherein `without departing lfrom-the scope lof the invention/which is defined in the l l appended claims.V x

What is claimed is: 1

.1. Ayielding pressure cushion of the chai'- acter described'comprising cooperating fixed and movable elements forming atop fluid l' pressure chamber of variable capacity, additional fixed and movable elements forming a lower.. fluid pressure chamber of variable capacity, a fixed element of one of said presv'sure chambers being located adjacent a movable element of the other chamber, and a connection between the movable elements of said pushionprovidedV externally of said chamers.v

f 2. A yieldngpressure cushion of the characo lstruction, being formedv essentially of only acter described comprising cooperating fixed and Vmovable elements forming a top air chamber of variable capacity, additional fixed and movable elements forming a lower air chamber of'variable capacity, a fixed element of one of said pressure chambers being located adjacent a movable element of the other chamber, air supply passages for said chambers, and a connection between the movable elements of said cushion provided externally of the fixed element of the top chamber.

3. In a press of the character described, a yielding pressure cushion comprising upper and lower fluid pressure chambers of variable capacity each chamber having a movable element and a stationary element cooperatively associated therewith, a fixed element of one of said pressure chambers being loc-ated adjacent a movable element of the other chamber, and means provided externally of said chambers for connecting the movable element of one chamber Vto the movable element of the other chamber.

4. In a prem of the character described, a yielding pressure cushion comprising cooperating fixed and movable elements forming a top fluid pressure chamber of variable capacity, additional iixed and movable elements forming a lower fluid pressure chamber of variable capacity, the fixed element of the top fluid pressure chamber having a bottom surface forming a stop for the upper surface of the movable element of the lower fluid pressure chamber, and means connected to the movable element of thetop chamber and extending down into abutting engagement with the upper surface of said lower movable element.

5. In a press of the character described, a yielding pressure cushion comprising telescopically engaged upper and lower piston Vand cylinder elements providing a top air chamber, supporting means fixing the lower element in the press, additional upper and lower piston and cylinder elements providing a second air chamber below the top air chamber, and a connection from the upper element of the top air chamber extending freely through said supporting means to the upper element of the second air chamber and provided at points spaced from the piston and cylinder axis.

6. In a press of the character described, a press bed, a pressure plate slidably guided in said bed, said plate .having a downwardly extending cylindrical wall and constituting a cylinder element. a piston element slidably guided in said wall, supporting means fixing said piston element to said bed and formed as an outward and downward continuation of said piston element, pins fixed to said cylinder element and extending down through openings in said supporting means, a lower cylinder element having an upper surface engaged by said pins and adapted to be moved signature.

ARTHUR A. BYERLEIN. 

